Capacitive Array Technology for Composite Rotor Blade NDI

Composite rotor blades are susceptible to a variety of damage mechanisms, including voids, delaminations, disbonds, impact and battle damage, matrix cracking and water intrusion. Current inspection practices do not provide adequate levels of sensitivity to defect conditions, cannot provide reliable defect identification and are subjective in nature, resulting in increased operating and maintenance costs. Improved nondestructive test methods are needed that can be integrated into automated test equipment to produce 3-D images of defects and internal blade conditions. This proposed Phase I program will address composite rotor blade NDI by introducing a new inspection capability based on advanced capacitive array technology. This technology offers unique capability for glass fiber reinforced polymers such as those used in rotor blades and has demonstrated capability to detect relevant defects in relatively nonconducting composite materials. JENTEK is currently developing capacitive array technology for ceramic matrix composites under a Navy Phase II program and for imaging density and thickness of asphalt paving under a program administered by the National Academy of Sciences. This proposed program will leverage on-going funding to demonstrate feasibility of a rapid, capacitive 3-D imaging solution for surface and internal defects in composite rotor blades.